Grinding machine



March 22, 1927.

J. MILLER, JR

GRINDING- MACHINE 5 Sheets-Sheet 1 Filed Nov.v2f1. 1924 l y- 2 ga/@dorfy 1 Jij" `March 22 1927.

J. MILLER, JR

GRINDING MACHINE 5 Sheets-Sheet 2 Filed Nov. 24. 1924.

5 Sheets-Sheet s J. MILLE-R, JR

GRI'NDING' MACHlNE Filed Nov.24. 1924 March 22 1927.

March l22 1927.

J. MILLER, JR

GRINbING MACHINE K 5 Sheets-Sheet 4 Filed Nov.24. 1924 Eweka/j' WMWSMWMarch 22, 1927.

J. MILLER, JR

' GRINDING MACHINE Filed Nov.24. 19244 5 Sheets-Sheet 5 horizontalsection taken online 5, 5, of

JOHN Mii.

'Patented Mar. ZZ, 1927.

'miren sfraiins Partnr for-Fics. t j

LER, JR., 0F BELOIT, W'ISCONSIN, ASSGNOR TO CHARLES H. '.BESLYv .AND vCOMPANY, OF CHICAGO, ILLINOS, A CORPORATION 0F LLINOS. f

GRINDING MACHINE. Y

Application i'ile'djNovember 24, '1924. Serial No. 751,744.. v

This invention relates to improvements in grinding machines and moreparticularly toY disc grinding machines used for the finishing ofcastings and work of like chanacter.

i movement @imparted to the grinding disc,

with the attendant advantages *hereinafter` more fully set forth.

The preferred embodiment of the invenltion is'disclosed in theaccompanying draw y ings in whichl Figure 1 is a view in elevation ofthe front or grinding end ofV` a disc grinder of the horizontal type; j1

Figure 2 is a view in vertical cross section taken on line 2, 2, ofFigure 1;

Figure 3 is an enlarged detail view in vertical section taken on line 3,3, of Figure 2;

Figure 4 isfa similar view takenon line 4, 4, of Figure 2;

ure 2 and y Figure 6 is a diagrammatic representation showing-thetypical curves inscribed. by the axis of the grin-ding disc and during.sev-v eral oscillations.

As is common in machines of this type,

the moving part-s are enclosed within a frame or housing, which'in thisinstance is integral with a vertical base or pedestal 1,`

. which rests upon the floor and which sup- Y u?, extending the fullwidth of the table andV ports the frame housing 2 in whichthe. drivingmechanism of the grinding disc is enclosed. The housing 2 is generallyrounded on vits' top side and owing to the .particular arrangement lofthe driving mechanism 'is provided with an additional housingB extendingabove the main housing and offset to the right Vof its vertical centerline. .As'clearly shown inFigures 2 andefthe work table 8 comprises acentrally located horizontal platform 8, having its surface slotted inthe -usualmannen soL that the va- 'f rious fixtures used for securingtheV work to' the table, may be bolted down. Surround- Ving the frontand side of the central platformy 8a is a trough 8b, while'at .the backof this platform is a deeper and wider trough forms the space in which.the grinding diskv I swings. l Y Y At the'forward end ofthe machine islocated the grinding disc 4, its spindle 5' rojecting through thehorizontally extending slot 6 in the front wall of the frame hous- 60`ing2. Integral with the frame housing and projecting forwardly from itsVfront wallis a curved wall 7 extending a short. distance beyondthe discandr enclosing the top and sides of the space in ywhich the grindingdisc swings and rotates." Immediately belowthe grin-ding'disc is avertically` adjustable work table 8, slidably mounted on vertical guideflanges 9, 9, through the` mediumof Vguide ways formed along the sideedges. of avertical guide plate 10, integral with the work table 8 andreinforced by two,transverse webs 10a-10a. The work table "is adjusted fvertically'by a screw shaft 11 journalle-dat its lowerend in a stepbearing 12 formed 75 integral with an extension 18j ofthe base or bedplate of the pedestal 1. Carried'at'the ylower endl ofthescrew shaft 10isa hand wheel 14 by means of which is elevated or depressed. Located inthe upper part of thej` frame Y housing 2 and within the portion of thehousing extension 3, limmediately yabovefthef` grinding disc 4, is aVhorizontal shaft 15 extending the vfull lenoth of the housing' and A55supported' V'at its ends in journal 'bearings' 16, 16, at theforward'and rear ends of the fraineihousing 2 by means of stub shafts15a, 15a, As clearly shown in Figure` 2, the portion of the shaft 15`intermediate its stub 90 shafts 15a, 15a is of greater diaineterand itsaxis is offset from thev axis of the journal I bearings or rotationofthe shaft, thus forming an eccentric 'bearing-15b whichr rotates withan eccentric motion as the shaft turns the work table i f so Aonv itsbearings. Journalled lupon andsuspended from the eccentricfbearing 15blof the shaft 15 is a swinging'motor support '17 consisting of a journalsleeveV 17a/extending i of the rear bearing 16, and integral larms 17?,17h., extending downwardly below the.4 sha-ft 15 and terminating in' aface plate 18 to which is bolt-ed a specially designed motor frame 19which has a corresponding face plate 19a; This motorframei'19supportsthe driving motor 20, having the usual bearings at eachend for the armature shaftN 'lll i drives the main eccentric shatt 15through the the grinding disc l,

2l of the motor.l The forward end of the armature shaft has directconnection with the Spindle 5 of the grinding disc which is likewisejournalled in the forward arn'iature bearing which is extended throughthe slot 6 of the front wall of the housing tothe back face of saiddisc, as clearly shown in Figure 2.

Formed integral with the rearinost .portion of the motorframe is avertical shaft `bearing 22, in which is journalled a drive shaft 23 indriving` connection with the rear end ofthe armature shaftby a pair ofspiral gear wheels 249' and 2lleyed to the adjacent ends of the armatureshaft and said drive shaft. itthe upper end of th-e drive shaft 23 is abeveled pinion 25, located just below the rear shaft bearing 16 andwhich meshes with a beveled gear wheel 26 which Y is keyed to the shaft15 and at the rear end of the eccentric portion tliereoi', between rearshaft bearing 16 and the rear end ot the journal sleeve 17a ot the motorsupport 17., From the foregoing description it will be understood thatthe motor 2O hangs freely lor is suspended from the eccentricy portionot' the shaft 15 immediately above, as is also in direct drivingconnection with the motor, and drivenV thereby at a high'frate of speed.Likewise, the motor Vdrives'hatt 23 and intermediate gear wheels, but atspeed considerably less than that ot the motor. By reason of theeccentricity of the bearing portion 15a supporting the motor, therotation ot the shaft imparts a verrticalioscillatory or reciprocatingmotion to the motor and grinding disc corresponding Y be described:

tothe amount of eccentricity or throw et' the eccentric portion 15ELturning on the Journal sleeve oi the motor support. rlhus, it is seenthat from the mechanism already described, two independent movement-sare iinparted to the grinding disc, namely, the rotation ot' the disc ata high rate oit speed about its horizontal axis and an accompanyingrVvertically oscillatory 'movement at a comparatively slow speed. Y

Another, or third, motion, however, is imparted to the grinding disc bymeans now to 0n the rear end stub shaft 15a oit the' main .shaft 15 ismounted a spur gear-,27 enclosed ustment.

with the traine housing and more specifically at the ends of the housingextension 3.

Referring now to Figures et and 5, there is keyed to the shaft 30 apoint substantially opposite the rear end oi the motor support journalsleeve 1TH, :in eccentric assembly consisting ol" a two part hubmeniber, each oart v32, 32, having an integral triangular shaped faceplate extending radially trom the hub portions in an upward and downwarddirection, as isl clearly-shown in Figure 3. The hubs 32 "-.vith their.tace plates are keyed sep-arn lyto the shaft with a space between, inwhichis a circular plate S3, havin` the torni of an eccentric sheave.vThis eccerif'c sheave is pivotally connected betweentl'ie face plates32a, 32 by means ot pin 3ft passing through the lewer apex of eachtriangu ar face plate 3L and through the sheave at a pointofli-et fromits center. The sheave is also rconnected. to the tace plates 32 bymeans ot a bolt which passes through the upward extending portion'oteach ot the face plates and a slot-33"l in the member 38, and describedabout the `pivotal pin S-las a center,thereby permitting the sheave tobe swung about the fixed pivot ioint to vary its eccentricity withrespect to the axis of the shaft 30. Between the slot 33 in the memberand the ifixed pivotal pin is a larger slot likewise subscribed aboutthe :lifted center 342 and through which the shaiit 30 esten/ls.Maiiiiestly, by virtue of this' adjustmcnt,V tue throw of the eccentricsheiive can be varied from concentricity lined V lll() with the shaft3() tothe maximum ot eccen- Y tricity permittedby the slot and pin ad-4if'i-onnteil on the Veccentric sheave E2-lis "n eccentric strap 8G havian integral a extending substantially at right angles toward therearniost depending` arm 17 of the motor support and terminating in at'orlred end 37. This tori-redV end 3? Vstraddles a lateral projectingboss 38 integralY with the nictor support below the shaft 15. A journalbin is in tinted in this boss, its ends having bearing in the forkedends ot the ec-` K centric arm.

' 'Having described the auxiliar7 eccentric shait drive and itsconnection with the ino- `tor support, the Voperation ofthe machine as awhole will now be explained. Bearing in mind the movements iiiiparted tothe grinding disc. by the motor and bythe eccentric motionvof the motorsupport, it will now be seen that a third movement is added bv theeccentric on the auxiliary shait S,"

which is driven trom the main shatt 15 through the interineshed spurYgears 2T and r29 atthe rear oi? the trame housing. rlhis motor andgrinding disc bach and torth, in an arc ot about 600, or 30 on either.side

third motion is a swinging or pendulum Vmovement which carries the motorsupport,

fthe motion resulting from the combination i finished surface. Intliesecond place. there "motions, first, 'the i'otation of the discabout itsl aXis;'second,`a vertical oscillatory movement in thedirection of animaginary line passing through `the axis of the spindleand the axis of the main eccentric shaft 15, and thirdly, the pendulummovement imparted from the secondary or. auxiliary shaft 30V through theeccentrici thereon. Obviously,

ofthree motions imparted simultaneously is one difficult to describe,butvan attempt has been made to illustrate what this motion would be, bythe'diagrammatic representation of Figure 6, which is intended toindicate thetypical path ofthe center of the disc as it swings bach andforth through4 several strokes or oscillations. From theV diagrainitwill be noted thatthe motionv isV quite irregular 'and without anysimple definite sequence or order of convolutions.

Moreover, an almost infinite number of motions can be obtained to 'suitthe various l kinds of work to be done, first, by changing the spurgears 27 and 2S to secure different gear. ratios, since by so doing, therelative speeds of the main and auxiliary eccentric' shafts will bechanged,`tlius varying the rate ofoscillations to the rate of verticalreciprocations, and hence, producing an entirely different movement.Secondly, by changing the't-hrow of the eccentricon the lsecondaryshaft. This is readily accomplished by loosening the bolt 35 whichclamps the eccentric sheave to the `face plates 32h and Vswinging. theeccentric sheave 33 bodily about the fixed pivotal pin 34, therebyincreasing or decreasing theeccentricity lor throw of the eccentric. 3,if the adjustment isV such that the maXimuni throw .of the eccentric isobtained by swinging the sheave to the left, the throw4 can bedecreased, even 'to' tlieextent of bringing the axis ofV the sheavecoincidentof the Yaxis of the shaft 30 with the result that an 'entirelydifferent niotionwill be produced.

Theadvantages of the oscillatory movement in i the grinding operationare numerous.' In thev first place,^assuming that the work is heldstationaryand brought in contact with the abrasive surface ofthegrinding disc, Vthere willv be ai/'constantly changing cutting surfacepresented to `the work which gives a much smoother finish i vvof a shaftjo'urnalled in the'. machine frame, and having an eccentric journalledbearing portion, a support .journalledon said `ec-`v andprevents thewear of grooves, in the is less tendency for the abrasive surface tobecome clogged with the grindings and gives the surface an vopportunityto free itself of the grindings, thus making for' speed-ier grindingaction. Andv finally, thel fact that the surface presented to the workis'con- Thus, asfin Figure i stantly changing,'distributes the wear overthe entire surface of thedisc, thus promoting more, the constantlychanging surface gives more opportunity for the heat generatedin thegrinding process to become dissipated,

overheated with the possibility of warping or distortion ofthe castingltalrii'igplace. I claim as my invention: A1. In a grinding machine,ytion of arotative shaft having an eccentric bearing portion, ajframesuspended fromV 3. In a grinding machine, the combination of a frame, ahorizontal shaft gournalled at its ends in said frame and havingintermediate eccentricbearing portions, a support 7 frame journalled ontheeccentricbearing portion of said shaft and depending therefrom, aspindle'journalled'in said supportfingframe, a motor mountedon saidframe and having direct driving `connection with Vlonger a'nd moreuniform wear. Furtherv '-tliusv preventing the work'from becomingL 'i5the combina-14 kportion and means for driving 'said shaftf Y said motorand driving mechanism connecting said motor with said shaft.

e. In a grinding machine, the combination o -of machine frame, ahorizontal shaft journalled'insaid frame, and providedV with aneccentricbearing portion, a frame journalled on said bearing portion anddepending therefrom, a grinding memberv journ'alled at the free end ofsaid frame and a motor in driving connection with said grinding element,and with said shaft. Y

5. In a grindinginachine, the combination of a `machine frame, a shaftjournalled in said niachinefranie and having an eccentric bearingportion, a support journalled on said bearing` portion` a vmotor mountedin said support, a .grinding diskv mounted on Ythe armature shaft ofsaidL motor and'means for driving said shaft comprising gearinginterposed between said shaft and the shaftV of the` motor.

i 6. In a grinding machine, the combination centric bearing portion, aspindle journalled in said support, a motor in driving connection withsaid spindle,.an auxiliary shaft in Y driven connection with said firstmentionedY v shaft, aconnecting rod connecting said auxiliai'y shaftWith Vsaid support, and driving mechanism operatively connecting saidmotor with said rst mentioned shaft.

7. In a. grinding machine, the combination ot a. machine frame, a shaftjournalled at its .ends in the machine traine, and having an iii- VVfromthe other ena oii'said armature shaft,

ICI

and a gear vhcel lteyedto the eccentric hearing ot said tii'stincntioi'ied'sliatt, and in driving-connection with said orive shaft.

8. ln a grinding machine, the combination of a shaft jonrnalled in themachine trame, and having an eccentric hearing portion, a motor supportjournalled on said hearing and dependingtherefrom, a motor mounted onsaid support, a grinding' disc mounted at one end oi the motor armaturesl att, a secrondaryv shaittiournalled in said trame and in drivenconnection VWith said iirst mentioned shaft, driving mechanism 1betweensaid motor and said iirst mentioned shaft and means Vcarried hy saidsecondary shaft and operatively connected with said motor support forimparting a predetermined movement z thereto,

9. In a grinding machine, the combination ot a trame, a pair .otparallel horizontal shafts journalled in said frame, means for drivinglsaid shai't, 'oneoit an eccentric hearing` portion, a supportjonrnalled'on said eccentric hearing portion, a motor driven spindlejournalled insaid support and means connecting said support and Vtheother ot sait shafts for impartingI a penduluni motion to said support.

10. Inv a grinding machine, the combination oi a trame, a pair ofoperatively connected parallelv shaft-s journalled in said trame andprovided With eccentric bea-ring portions, a motor support jonrnalledYon the veccentric hearing portion of one ofV said shafts, a motor and agrinding disk carried hy said motor support, an eccentric strapiournalled on the hearing` portion on the f other shaft and operativelyconnected with said shatts.

said motor support, and speed reducing` gearing interposed'ivith saidYmotor andk oneY of ll. In a grinding machine,rthe combinationot atraine, a horizontal shaft jonrnalled at its ends in said traine, andprovided with an intermediate eccentric hearing portion, a

v motor suspended from said shaft through the medium of a journal sleeveonv said eccentric said shatts havingl hearingl portion, a grinding disckdirectly con? nected with said motor, a secondary shaft driven fromsaid iirst nientionedf'shatt', an eccentric on. said secondary shaitandoperatively connected with said motorsupport' and means tor rotating),lsaid first mentioned shaft.

12. ln a. grinding` machine, the coiiihination or" a trame, a shaftjournalledin said frame and havingan eccentric hearing por-V tion, asupport jonrnalled on said eccentric hearing and adapted to svving`aloout a horizontal axis, a motor drivenspindle'mounted Y on saidsupport, a grinding disk mounted on said spindle, a secondary shattodset from said Erst mentioned shait't and having driving'connectiontherewith, means operated hy Asaid secondary shaft and connected Wit-hsaid snpporJ tor imparting,Y an oscillatory movenient thereto, andmeansrtor imparting a relatively reduced vand substantially uniformpedot rotation to said shaft.

13. in a grinding machine, the combination ot a shaft havingV aneccentric hearing portion, a trame depending trom said shaft andjournaled on said eccentric hearing portion, a. s iindle journaled insaid supporting traine, a motor mounted on said supporting iframe andhaving driving` connection with said spindle and said shai't, and meansdriven hy said shaitl tor imparting oscillatory motion to saidsupporting trame.

le. n a Vgrinding,` machine, the combination ot a` shaft having aneccentric hearing portion, a supporting'trame joninaled on saideccentric hearing` portion, a motor driven spindle mounted onvsaidsupporting trame Vand'loelow said shaft, a shaft rotative about anairisparallel with said iirst Amentioned shaft, means operativelyconnect said motor support, and means driven lov said motor torimparting a relatively sloiv unii'orm Vspeed Aot rotation to said lastinentioned shaft to oscillate said motor support.

Signed at Chicago thisQOth day or Noveinher,'1924.

soi-iN MILLER, ai.'

